MSAN (Muliti Service Access Node) Soft switches

1Atzwanger Joachim PTM TRA 1

MSAN

(Muliti Service Access Node) Soft switches

Atzwanger Joachim

ITSF 2009 ROM

2

Overview

• Challenge for Telekom Austria

• Clock requirements

• Syncronisation Concept

• 10GWAN contra 10GLAN

• MSAN synchronisation

• Testresults Atzwanger Joachim NP CDI

• Mobil Backhauling

– Sync supply with 1588 via Fiber over GbE

• Substitution of digital exchanges

– Maintain Sync requirements for ISDN BRA&PRA

• Reduce maintanance costs per year

3

Challenge

Atzwanger Joachim NP CDI

4Atzwanger Joachim NP CDI

Overview MSAN, Soft switch

PEV2A

PEV1B

Call Agent1Call Agent1

PEV2B

PEV1A

Fiber ChannelTA-DWDMprotected

USP USP

active backup

GWCGWC

Site A Site B

2xGE

Fiber Channel

MGW

Call Agent1

USP

active

GWC

Development

2x

2x

Bladecenter

T

3x BaseT

3x BaseT

MGW

Bladecenter

T

2x BaseT

2xBaseT

POP Site 1

2x GE

Hairpin

IPS

2x GE

Hairpin

IPS

2x GE

Hairpin

IPS

2x GE

Hairpin

IPS

ISAM/MSAN Development

ISAM/MSAN Integration

Service-Lines

2xGE

2xGE 2xGE

Clock required

Legende:

GigE SX

GigE LX

GigE TX

Clock required

Clock required Clock required

Clock required

Clock requiredClock required

5

Clock requirement ISDN

• Sliprats G.822, ETR 299 for IDSN BRA und PRA

• Transit Network: 0,3 slip/day

• Local Network: 2 Slips/day

0,3 Slips/day should be reached


SETS

Select

C

Select

C

Select

A

SETG

T4

T0

SyncE

ETY -> TE

External T3

Clock concept MSAN ISDN BRA

Signal

prozessing

Buffer xxxxLayer 2

Switch

BRA:

Signal

prozessing


NT LoopTiming

Lin

e C

ard

Buffer 1

Buffer 2

Signal

prozessing Layer 2

SwitchSignal

prozessing

Lin

e C

ard

Clock concept MSAN ISDN BRA


Signal

prozessing Layer 2

SwitchSignal

prozessing

BRA1

NTLoopTiming L

ine C

ard

IPTra

nsport

netw

ork

f0

f1BRA2

NTLoopTiming

MSAN 1

MSAN 2

Buffer 1

Buffer 2

Buffer 1

Buffer 2


Why Slips

Clock accuracy 1 Frameslip in

10E-12 700 days

10E-11 70 days

10E-10 7 days

10E- 9 17 days

10E- 8 11,75 hours

10E- 7 10 hours

10E -6 1 minute

10E -5 6 seconds

Frameslips: PCM31, Buffer 125µsec

If f0 ≠ f1 one of the buffer will come to his max.

threshold and then Bits will be droped.

Comply to15ppb forUMTS

9

10GWAN contra 10GLAN

10G-WAN = Layer 1 STM-64 Interface => STM N Overhead


STM64-OH: B1, B2, S1 + AIS/RDI

10

10GWAN contra 10GLAN

WAN PHY mode (10GWAN = STM64) on 10GE Interfaces

detect bit-errors on underlying WDM-Systems per Segment - so it´s needed to troubleshoot complex networks

Multiplex section

B2 parity

N x 3 bytes for Bit error monitoring over the whole multiplex section are availabel. The BIP 24 value will be calculated to even parity over all Bits of the frame exept the lines 1 to 3 of the ROHS (Regenrater section overhead) and transmitted in the next frame



10GE WAN Synchronization: Standards Conflict

802.3ae std

Ethernet transport was not intended to be used for network synchronization

Prohibits “network” clock recovery: pg 372 table 50-2

Relies upon free-running OSC

Since WAN framing based on SDH/SONET

SSM conveyed in physical layer S1 byte

S1 set to a fixed QL=DUS (do not use for sync): pg 372 table 50-2

G.8262 & G.8264

Defines network timing distribution support using Ethernet transport physical layer

Requires “network” clock recovery based on hierarchical clock distribution

All framing convention references IEEE 802.3

Therefore, physical layer assumes std Ethernet framing/preamble

Conveys network clock quality level via (L2) messaging defined by slow protocol


Overview: 10GE WAN Synchronization Feature Issue

IEEE 802.3ae

The WAN Interface Sublayer (WIS) is an optional PHY sublayer that may be used to create

a 10GBASE-W PHY that is data-rate and format compatible with the SONET STS-192c

transmission format defined by ANSI, as well as the Synchronous Digital Hierarchy (SDH)

VC-4-64c container specified by ITU.

The purpose of the WIS is to allow 10GBASE-W equipment to generate Ethernet data

streams that may be mapped directly to STS-192c or VC-4-64c streams at the PHY level,

without requiring MAC or higher-layer processing.

ITU-T G.8262 & G.8264

G.8262 specifies the Ethernet clock performance

G.8264 specifies the Ethernet SSM equivalent process

SSM is based on a L2 802.3 slow protocol

Clock recovery based on network traceable coordination of physical layer signal


Overview: 10GE WAN Synchronization Feature Issue

Option 1

Address conflict between IEEE & ITU-T and modify 802.3 to allow

Clock recovery

S1 byte sync messaging

Risk/Benefit

Slow process, but consistent & coordinated result

Assures network interoperability

Option 2

Provide proprietary solution:

Enable SONET/SDH L1 clock recovery

Enable SSM messaging via L2 Ethernet slow protocol

Risk/Benefit

Quick process

Proprietary solution – no/little interoperability

14

Additional frequency back up points

• GPS OK

• SSU OK

• PTP Slaves OK

Stressd Slave:

Frequency

accuracy 1ppb


Holdover PTP Slave: 1 Week about 15ppb

Feature SyncE IEEE1588 Command

Transient response To 10 times longer *as SyncE

*Will be inproved with Fast Lock etc.

Frequency accuracy Better

1xE-10

x ppb* •With traffiv >50%

etc…

Clock accuracy independent from trafficload, framesizes,

Yes NoCompensation with transparent Clock

Clock selection with SSM Yes 2. Grandmaster

Frequenzsynchronisation Very good good

Phasensynchronisation no Yes

+

+

+

+

+

SyncE contra 1588

+

+

+

Feature SyncE IEEE1588 Command

Bandwith No Down 148kBit/sec Up ca. 45kBit

64 Syncmessages/sec

Pollicy MPLS No Yes

Holdover 2 days G.813 Option 1

Better 15ppb/week

Alarms,

metrics suitable for SLA

SSM ? In future

+

+

+

++

SyncE contra 1588

++

17

Impelementation ruls:

• Clock distribution over 2 Ways:

Aggregation 1 and 2

Topology: Ring: OK

Chain: addtional frequency input points

• SSM from source (MPLS Node) to sink (MSAN)

• Alarms MSAN: Holdover, Change of SSM Value

• SNMP Traps


18

Clock distribution

NM

NM

MPLS Network

Synchronous Ethernet (SyncE) +

IEEE1588

Core Sync-Distribution via SDH-RIFU, OTN

Core Sync-Distribution via SDH

Sy

nc

L

ev

el 1

Sy

nc

Le

ve

l 2

SSU

Sy

nc

Le

ve

l 3

Digital switches, nx64k, SDH,

SSU

PRC SRC

SSU

GPS

SSU

From SBG AL over SDH

SBG/ItzSBG/Al

SSU

GPS

SDH

IEEE1588

Grandmaster

Blade

Clock distribution 2009

synchronization network connection

redundant synchronization network

connection

FOKUS 2009

· SSU

· Upgrade NMS

· Rollout 1588 Mobile

Synchronisation

Forecast 2010/11

· e2e Sync-Services

· Rollout SyncE

· Redesign Core-Sync

GPS

ATVS2/18 managed

ATV

GPS

P T

P

1588 SLAVE

Boundary clock/

Transparent Clock

1588 SLAVE

Node B

Customer

NM

NM

NM

NM

NM

NM

NM

NMS Patch

NMS Interation

MSAN

Clock distribution 2009 V2.2 Atzwanger Joachim NP CDI 2009

SSU

GPS

BITS

PT

P

PT

P

PT

P

PT

P

Syn

c E

PT

P

BITS


MSAN Syncronisation Concept Phase 1

20

MSAN Platform:

Services:

• Pots

• IDSN BRA & PRA

• Leased Lines

Technologie

• SHDSL

• VDSL

• GPON

10G Uplinks in future



MSAN Syncronisation Concept Phase 3


PE2031

PE2032

10GWAN

1G

10GWAN 10GWAN

Ethernet

MPLS

Test-Plattform

PE2035

PE2036

1G SyncE

1G SyncE

WL222090-

ARSENAL101

ISDN-Tester

Clock 2,048Mbit

1/3/1

1/3/3

1/1/19/1/1

WL222078-

ARSENAL105

Clock 2,048Mbit1G SyncE

optional step 2

step 1 SyncE

1G

1/5/1

1/3/4BITS

BITS

BITS

lag-1

lag-2

lag-3

1/1/9

ISDN-Tester

Test environment for SyncE tests

ANT20Jiiter & Wander


MSAN: Wander generation

Comply with:G.8262 8.1.1 EEC Option 1 Wander generation


MSAN: Short-term phase transient response

Comply with:G.8262 11.1.1 EEC-Option 1 Short-term phase transient response


MSAN: Holdover

Comply with:G.8262 11.1.1 EEC-Option 1 Long-term phase transient response

26Atzwanger Joachim PTM TRA 26

Many Thanks!

Questions?

[email protected]

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MSAN (Muliti Service Access Node) Soft switches